When it comes to climate change either you're with us, or you're on the other side. Well at least that's how it appears at times. So what happens when someone from one camp says something that appears to support the other?

In the last few days, pro- and anti-climate change blogs have gone into overdrive over comments made at a US Congressional hearing into climate science.

To understand what it's all about, you need to go back to November 2009. One of the biggest science stories that month was the 'leaking' of emails from the Hadley Climate Research Unit (CRU) at the University of East Anglia, including the unit's head Professor Phil Jones.

The leak would later become known as 'Climategate'.

While most of the emails contained nothing more than benign exchanges, a small number caught the eye of both the media and the public at large.

One email referred to Jones and colleagues using a technique referred to as 'Mike's trick' to explain an apparent decline in temperatures observed in tree ring data since 1950.

A series of enquiries soon followed and all cleared the researchers of any wrong-doing. But the emails increased the level of scepticism and scrutiny towards climate science.

Anthony Watts, a former television meteorologist and creator of the blog WattsUpWithThat, has been a vocal critic of some of the methods used by climate scientists. One of his biggest criticisms has been the use, or misuse, of data from weather recording stations.

Watts, along with a large group of volunteers, have catalogued numerous cases of data from weather stations being unreliable or mishandled.

One area of concern is 'urban heat island effect' (UHI) due to increased housing and other infrastructure close to a weather station, which can typically cause an increase in temperatures recorded.

One example is the weather station located at Laverton, 17 kilometres south-west of Melbourne. In the past 20 years, urban expansion has seen this former 'rural' site now surrounded by homes. As a result, temperatures recorded by this station must be adjusted 'down' to maintain the continuity of the data over time.

Another example of changes in data discontinuity is the Darwin weather station. It was originally located next to the post office close to the city centre, but during World War II was moved to Darwin airport.

Changes such as these, along with the quality of equipment and the way data is recorded, affect its overall quality.

As a result, the data used by climate scientists needs to be adjusted - or discarded - to ensure apples are compared with apples.

This brings us back to Phil Jones and Climategate. How well adjusted is the data and are climate scientists 'cooking the books' to suit their needs?

Professor Richard Muller of the University of California, Berkeley has for some time been critical of the techniques used by some of his colleagues.

Last year, he gave a lecture in which he claimed he would no longer read papers authored by certain researchers, due to the Climategate scandal.

BEST's aim is to examine data from all 39,390 available temperature stations around the world, regardless of their quality, to test the results of previous studies by NOAA, NASA and Hadley CRU.

In February, Watts threw his weight behind BEST by announcing he would share his methods for analysing temperature data.

Last week, Muller presented BEST's preliminary findings to a US congressional hearing. The results weren't what he, or the sceptics, expected.

"In our preliminary analysis of these stations, we found a warming trend that is shown in the figure. It is very similar to that reported by the prior groups: a rise of about 0.7 degrees Celsius since 1957," says Muller.

He went on to say: "Did such poor station quality exaggerate the estimates of global warming? We've studied this issue, and our preliminary answer is no.

"Thus, although poor station quality might affect absolute temperature, it does not appear to affect trends, and for global warming estimates, the trend is what is important."

Watts responded with a letter addressed to the committee claiming Muller's work is incomplete and lacking peer-review.

On his blog, Watts says: "BEST hasn't completed all of their promised data techniques that would be able to remove the different kinds of data biases we've noted.

You have no doubt been hearing a lot about the Paris Agreement and know that it pertains to climate change, but are too embarrassed at this stage to ask for an overall explanation of what it's all about.